I previously suggested this battery but it supplies too much voltage and causes flaky operation and possibly damage over time.

Probably will not buy any 3rd party battery now...the *best* reviewed 3rd party batteries I've tried were Wasabi's which indeed at least did not try to fry your camera and are much cheaper, but they absolutely become weaker batteries rather quickly, so you really don't save money anyways if you consider just battery life vs money. If you consider battery life + reliability + cost, there truly is no reason to buy 3rd party batteries.